Boat-hull.



J. CAMPBELL.

BOAT HULL.

Y APPLICATION FILED mus, 1911'. 1,055,874. Patented Mar. 11,1913.

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J. CAMPBELL.

BOAT HULL.

APPLIGATIQ 11111111111111 1.

1,055,874. Patentd Mar. 11,1913.

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JOHN cAmPiiELt,

OF MINNEAPOLIS, MINNESOTA, ASSIGNOB OF .ONE-HALF TO THOMAS E. MODERMOTT,F MINNEAPOLIS, MINNES OTA.

' BOAT-HULL.

gimm filed m 6, 1911. Serial No. 525,524,

Be it known that I, Jorm CAMPBELL, a

" citizen of the United States, residing at- Minneapolis, inthe'coiintyfofHennepin and State of Minnesota, have invented certain newand useful Improvements in Boat- Halls; and I d'o hereby declare thefollowing to be a full, clear,nand exact description of the invention,such as will enable others skilled in the artto' which it appertams tomake and use the same.

My invention has for.its object to provide a launch or motorboat ofthe'highest possible speed capacity, and, tothis end, the inventionconsists of the novel constructionand arrangement of parts hereinafterde- 'scribed and defined in-the claims.

In designing the hull -or body oft-his motor boat, I have made the samemuch in the.form of a fish. That. is, the 'largelor relatively wide bodyportion'is 'placedi'in front close to thebow and a long narrow tailportion-is extended at the stern. -The cock-pit for the engine and thepassengers is arranged in the relatively-wide front portion and th tailor narrowedstern portion is preferably made an -'air-tight compartment.Also, as'afea-tdre of .the invention, Iprovide two propellers, onelocated at the of the narrowed stern-orf tail and the other locatedbelow theinte'rmediate poi" tion of the hull, preferably slightly at theBoth of these pro rear of the cock-pit. pellers may, and preferablyLWillbe, driven from (the same engine; The rear propeller may have its axisand shaft horizontally extended, while the front or lower propeller willhave its axis and shaft inclined. The rudder is preferably mountedbeneath the boat just at the rearof the front or lower propellen' f'- Inthe accompanying drawings which illustrate the invention, likecharacters indicate like parts throughout the several views. 7

Referring to the drawings, Figure 'l-is aperspective view, showing theimproved boat; and Fig. 2 is a plan view thereof, with some parts brokenparts sectioned.

The relatively-wide body or front portion 1 of the boat hull preferablyextends about half the entire length of the hull, and the portion 2extends approxi-' narrowed 'tail mately the other half of the length ofthe by the rapid passage of the boat through 'thewatier.

explosive type.

that may be imparted to the boat with the away and some i' lflcation ofLetters Intent, Patgnted Mar. 11, 1911;.

' hull. The body 1....1 "tail portions 1 and 2 are united by graduallycurved lines which are designed to best adapt themselves to the wake orroll of the water produced The numeral 3 indicates th which is formedint-he body 1, as already indicated, and the numeral 4 indicates the.

air-tight compartment formed withinthe tail portion 2.

The numeral 5 indicates the rear propeller and the numeral 6 the frontorlower propeller, the shafts of which will be extended intothe'cock-pit'and, as already stated, preferably connected to a commonengine or motor, not shown, but which would preferably of themulti-cylinder The numeral 7 indicates the rudder'which is mpunted atthe rear front propeller '6, as s hdwm-in a bracket 8 secured to thebottom ofthe boat. This rudder may be controlled by any suitableconnections, not .shown.' p

Boat hulls, as generally designed, have such short stern portions-orthese stern portions are so abruptly terminated that, under high speed,very greatsuction and back-- draw is produced on the-boat hull. The longgradually narrowing tail rtion2 re-' duces to a minimum the 'backraw ordrag of the boat hull under high speeds and, hence, correspondinglyincreases the speed motor of any determined power. Also, the arrangementof the propellers increasesthe speed capacity of the-boat. -The rearpropeller 5 produces a direct forward pressureon the boat while thefront propeller 6 produces a pressure which is mainly directly forwardbut which is also slightly upward,

so that the draft of the hull, under high speed, is somewhat decreased.

The air compartment or chamber in the 100 tail of the boat hull gives abuoyancy which is required to keep the hull approximately level evenunder high speeds and, furthermore, it berves as a safety device toprevent sinking of the boat in case ofaccident.

By reference to Fig. 1, it will be noted that the body portion 1 andtail portion 2 of the hull are approximately the same depth throughout.This is important where the long tail or stern is employed and is a nocockpitfeature which, combined with the said long tail, makes itpossible to keep the boat hull approximately horizontal under allspeeds.

What I claim is:

1. A boat hull having'arelatively wide body portion extended immediatelyrearward from its bow and'having a relatively narrow and long tailportion extended rearward therefrom on curved Concave lines, the

said bod and tail portions having approximately t e same depth. i

2. A boat hull having a relatively wide body portion extendedimmediately rearward from its bow and having arelatively Copies of thispatent may be obtained for and the said tail portion being formedhol-\2o low and air tight.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN CAMPBELL.

Witnesses:

HARRIET A. CREW, HARRY D. KILGoRn.

five cents each, by addressing the Commissioner of latentsv Washington,D.C. 4

